Fuel control mechanism for heat apliances



Feb. 3, 1959 D. F. DRow FUEL CONTROL MECHANISM FOR HEAT APPLIANCESZfiheets-Sheet 1 Filed Jan. 30, 1952 :EIIfEil I v M w 3 mm m N w u n w AIII. HA

ed States. e

FUEL conrnor. MECHANISM FOR HEAT 7 APPLIANCES Donald F. Drow, LosAngeles, 'Calif., assignor to Minneapolis-Honeywell Regulator Company, acorporation of Delaware Application January 30, 1952, Serial No. 269,083

7 Claims. (Cl. 158'- 131) The invention relates to safety controls forheat appliances utilizing an intermittently operated main burner ignitedby a constantly operating pilot burner, and more od of obtaining this100% operation involves the use of a double type valve constructionseparately controlling the fuel flow to the main and pilot burners. Thisis frequently done mechanically by the use of a pair of coplanar,concentrically arranged valve seats for controlling flow throughseparate passages to the main and pilot burners, and which aresimultaneously engaged and closed off by a valve movable to such seatsunder the control of thermostat means responding to an extinguishing ofthe pilot burner. 100% or complete shut off operation is important inconnection with certain fuels such as liquid petroleum gases and otherheavier than air fuels which may provide a dangerous accumulation offuel from the small pilot flow.

One class of safety controls of the above character is what may betermed the manual resettable type in which the thermostat means releasesthe valve for automatic closing (under spring action) upon extinguishingof the pilot burner, and the valve is subsequently displaced toopenposition and into operative attachment of the thermostat means by whatis referred to as a reset means-- most commonly a manually displaceablemember. Another refinement made in controls of the manually resettabletype has been the provision of means for preventing the fiow of fuel tothe main burner during the resetting operation and igniting of the pilotburner. Controls incorporating this feature are frequently referred toas safe lighting in that there is removed by the provision of suchfeature the hazard, otherwise present, of the burning of the hand of theperson relighting the pilot burner. The safe-lighting provision has beenaccomplished mechanically in various ways principally by a structurallocking against movement of the reset means in the normal open positionof a secondary valve inscrted in the passage to the main burner, or bythe provision of means for automatically displacing to closed positionsuch a secondary or auxiliary valve during the resetting operation.

It is an object of the present invention to provide a fuel controlmechanism of the character described employing an improved system andarrangement and co action of parts which will provide the 100% andsafelighting features above discussed, while avoiding the use 2,871,930Patented Feb. 3, 1959 "ice and structures by which these features havebeen heretofore accomplished and the attendant disadvantages thereof. Itis therefore an object of the present invention to provide a safetycontrol mechanism of the character described Which is simple andstraightforward in its design and operation and is yet composed of aminimum number of sturdily formed parts designed and arranged for, andco-acting to produce, completely fool-proof operation over a very longperiod of use.

Another object of the present invention is to provide in a safetycontrol mechanism of the character described an improved form of resetmechanism functioning in a simple, straightforward and fool-proof mannerand positively preventing the flow of fuel to the main burner during theresetting operation and until the pilot burner has been ignited and itsoperation properly established.

A further object of the present invention is to provide a safety controlmechanism of the character described which is designed for compactnessand ease of construction and assembly which enhances its range ofutility and reduces its cost.

The invention possesses other objects and features of advantage, some ofwhich, with the foregoing, will be set forth in the followingdescription of the preferred form of the invention which is illustratedin the drawings accompanying and forming part of the specification. Itis to be understood, however, that variations in the showing made by thesaid drawings and description may be adopted within the scope of theinvention as set forth in the claims.

Referring to said drawings:

Figure l is a plan view of a fuel control mechanism constructed inaccordance with the present invention.

Figure 2 is a cross-sectional view taken substantially on the plane ofline 22 of Figure 1.

Figure 3 is a fragmentary cross-sectional view taken substantially onthe plane of line 33 of Figure 2.

Figure 4 is a fragmentary cross-sectional view similar to Figure 3 butshowing the control valve turned to light position.

Figure 5 is a fragmentary cross-sectional view similar to Figure 3 butshowing the control valve turned to 01f position.

Figure 6 is a fragmentary cross-sectional view similar to Figure 2showing the reset mechanism in an inserted (manually displaced)position.

Figure 7 is a fragmentary cross-sectional view similar to Figure 6 butshowing the reset mechanism in a normal (manually released) position.

Figure 8 is a perspective view of a part of the reset mechanism.

Figure 9 is a diagrammatic representation showing the main burner, pilotburners, the thermostatic means and the fuel control mechanism in theiroperative relationship.

The safety control mechanism of the present invention and as illustratedin the accompanying drawing consists to a main burner 3 of a heatappliance; a manually enof the more relatively complicated types ofmechanisms gageable and displaceable reset means 13 for the valve andits thermostat means 27; a passage 14 by-passing the valve 11 from theupstream side for taking off pilot gas during the resetting operation; avalve 16 controlling the flow through the by-pass passage 14 andconnected to the reset means 13 for operation thereby during theresetting operation; and a manually controlled valve 17 of the multiplepassage and position type having inlets 18 and 19 connected to thepassages 12 and 14 respectively and having outlets 20 and 21 forconnection to 3 the main and pilot burners respectively; the severalparts having their operations so correlated and their interconnectingpassages so arranged as to insure and make fool-proof the 100% andsafe-lighting operations hereinabove discussed.

Preferably the several parts are unitarily assembled in a casing orhousing 22 providing the main passageway 12 therethrough leading from aninlet opening 23 adapted for connection as by conduit 24 to source offuel such as gas, and being enlarged interiorly to provide a chamber 26for accommodating the valve 11 and its thermostat control means 27 andportions of the reset means 13.

The thermostat means 27 may be of any of the types commonly used inpilot safety valves such as a bi-metal latch as disclosed in JenkinsPatent No. 2,322,520, issued June 23, 1943, or of the deflecting tubetype disclosed in Drow Patent No. 2,530,942, issued November 21, 1950,or of the thermo-electric type as herein illustrated. This latter typeis composed of a thermo-couple 4 which is mounted for heating by thepilot flame 1 for generating an electric potential which is applied to afield winding 28 provided on a magnetic core 29 which functions so longas energized to hold in attracted position an armature 31. Uponextinguishing of the pilot flame and ensuing collapse of the magneticfield, the armature 31 is released from the pole faces 32 of thehorseshoe core here depicted for displacement therefrom under springaction to effect a closing of valve 11. For convenience, binding posts33 and 34 are provided on an end cover 36 of a case 37 provided for themagnetic core 29 and its winding 28 and armature 31, for connection tothe leads of the thermo-couple. The thermostat means 27 here employedthus has, in common with the other types of thermostat means noted, apart 31 which is movable between caught and released positions and itsmaintenance in caught position is dependent upon the existence of flameat the pilot burner.

In accordance with the present construction, the valve 11 and thermostatpart 31 are mounted for aligned and coaxial movement so that movement ofthe part 31 from caught to released position, from left to right asviewed in Figure 2, will be accompanied by a similar left to rightmovement of the valve 11 from open to closed position.

A seat 38 for valve 11 is provided by an interior wall 39 of the housingdefining the inner end of a valve chamber 26 adjoining passage 12. Ashere shown, the outer normally open end of chamber 26 is closed by theinsertion therein of the case 37 of the thermostatic means, the latterbeing secured and sealed by a ring nut 42 against an internal shoulder41 provided by the housing, thus placing the thermostatic means indirect alignment with valve 11. The latter is here mounted forreciprocation to and from the seat 38 by means of a valve stem 43secured to and projecting axially from the opposite sides of the valve,and having one end portion 44 slidably mounted within a bore 46 providedin a protuberance 47 forming part of wall 39 at the interior side ofvalve seat 38.

The opposite (left) end portion 48 of valve stem 43 is here slidablymounted within a tubular extension 49 fixed to and projecting axiallyfrom the armature 31, the tubular extension 49 being in turn supportedco-axially for reciprocation in a bearing 51 provided at the inner endof case 37. Secured to the inner free end of the tubular extension 49for movement therewith is a generally disc shaped part 52 thus supportedin axial juxtaposition to valve 11 for displacement of the latter toclosed position upon movement of the armature 31 to its releasedposition.

In accordance with the present construction spring means is provided forconstantly urging valve 11 and the thermostatically actuating part 52towards each other and to the closed position of the valve and thereleased position of the part 31. In the construction illustratedmatically opened upon depressing the this spring means includes twohelical springs 53 and 54. Spring 53 is mounted about the valve stemportion 44 in compression between the valve 11 and the protuberance 47so as to constantly urge the valve 11 towards thermostatic part 52 andto an open position. Spring 54 is mounted about the tubular extension 49and in compression between the end wall 56 of the case 37 and part 52,so as to constantly urge this part and the integrally connected armature31 to the right, as viewed in Figure 2, thus constantly urging thedisplacement of armature 31 from its caught to its released position andpart 52 toward valve 11 and its closed position. Spring 54 is somewhatstronger in its action than spring 53 so that when the armature 31 isreleased from the pole faces 32, spring 54 will overpower spring 53 toeffect a closing of valve 11.

Cooperating with the valve 11 and thermostatically controlled shut-offmechanism described above is the reset means 13 which here includes awedge shaped member 57 for effecting, upon displacement in onedirection, a separation of the valve and part 52 thus co-acting with thespring means above noted to hold closed valve 11 while displacing part52 to caught position. Assuming the pilot burner ignited and the magnetenergized and the thermostatic part thereby held in caught position,spring 54 will be immobilized and a return movement of the wedge member57 will permit an opening of valve 11 under the influence of spring 53.Wedge member 57 is here mounted for reciprocal motion perpendicular tothe axis of the valve 11 and part 52 by securing its outer (widest) end58 to the inner end 59 of a shaft 61 carried by the housing forreciprocation perpendicular to the aforementioned axis. Preferably theshaft 61 is mounted through a bore 62 in a plug 63 closing an opening inthe housing provided for convenience in mounting of the parts. The outerend portion of shaft 61 projects from the plug 63 for manual engagementand is normally maintained in a retracted (outwardly extended) positionby a helical spring 64 mounted about the shaft 61 in compression betweena head portion 66 provided on the outer end of the shaft for manualengagement and a washer 67 at the outer side of plug 63, the washer 67here holding in compression a packing gland 68 mounted in a grooveprovided in the plug surrounding the shaft.

As hereinabove noted by pass passage 14 is provided for leading gas fromthe upstream side of valve 11 to the pilot burner during the resettingoperation which requires passage 14 to be closed during normal runningoperation, and the valve 16 above noted, is provided in the passage 14and connected to the reset means 13 so that the valve is open onlyduring the resetting operation. For convenience and as a feature of thepresent construction, valve 16 is provided directly on the inner end ofshaft 61 for movement to and from a valve seat 69 provided at the innerend of plug 63. In this manner valve 16 is normally held closed byspring 64 urging shaft 61 to an outwardly extended position, but isautoshaft during the resetting operation. Passage 14 is formed in thehousing 22 and connects to a side of plug 63 where the passage iscontinued through the plug to an enlarged portion of bore 62 forming acontinuation of the passage to the valve seat 69 and chamber 26.

In order to permit the wedge to properly follow the relativelytransverse movement of the thermostat part 52 and valve 11 perpendicularto the line of displacement of the wedge member during the re-settingoperation, the wedge member is preferably pivotally secured to the innerend 59 of shaft 61. As here shown this pivotal attachment is effected byextending a reduced pin like end portion of the shaft through arelatively larger opening in the end 58 of the wedge member, and forconvenience expanding the outer end of the pin extension to preventdetachment. For simplicity and ease of construction the wedge member 57may be formed of sheet E J metal as illustrated in Figure 6 whereinitwill be seen that opposite sides 71 and 72 are folded in parallel spacedrelation, perpendicular to the end 58 above noted, so as to therebydefine a slot 73 between the sides to accommodate the valve stem portion48 upon insertion of the sides 71 and 72 between the valve 11 andthermostat part 52. Sides 71 and 72 are formed with a flat face 74adapted for sliding engagement with a flat face 76 provided on the backside of valve 11. Adjacent their inserted ends 77 (opposite end 58), thesides 71 and 72 are formed with a level or parallel opposite sideportion 78 which is adapted to normally engage a flat end face 79 onmember 52. Contiguous to portion 78 and extending therefrom to the end58, are relatively inclined por tions 81 which upon advancement of thewedge member during the re-setting operation are arranged to engage asimilar tapered or conical face 82 on the part 52 contiguous to face 79.In the present construction of the wedge member and associated valve 11and part 52 there is a relatively small area of contact whereby frictionbetween the members is reduced to a point where smooth displacement ofthe parts is eifected during the re-setting operation without liabilityto sticking or jamming. It will also be noted that the level or parallelportions 78 are in position between the part 52 and valve 11 in thenormal outwardly extended position of the reset means. There isaccordingly at least a preliminary insertion of the wedge between thevalve and part at all times.

The manual control valve 17 above noted completing the safety featuresof the control is preferably of the rotary plug or cock type having aconical shaped plug valve member 83 mating with and journaled forrotation upon a complementary tapered wall 84 formed in the housing 22and extending divergently to an outer side 86 to provide an open borefor receipt. of the conical plug 83. The plug member 83 is here securedin the bore by a retainer spring 89 held in compression between anannular shoulder 88 provided on the member 83 and a cap 87 secured tothe outer side 86 of the housing.

As will be seen from Figure 2 the bore for the plug member intersectsand provides a continuation of the main fuel passage 12 at thedown-stream side of valve 11.

It will also be noted that plug member 83 is formed with an axiallyextended bore 91 registering with passage 12 and thus forming the maininlet 18 to the control valve. The main fuel outlet 20 is provided inthe housing 22 and'extends to the wall 84 at the side of plug 83 forregistration with a transverse passage 92 in the plug 83 extending fromthe central bore 91. As will be seen from Figure 3, outlet 20 is definedas the valve terminal end of a passage 90 formed in the housing leadingto a fitting 95 for main burner conduit 100. Rotation of the plug to theposition "llustrated in Figures 1 and 3 places port 92 in registrationwith passage 20 thus constituting what is here denoted as the onposition of the valve wherein, so far as valve 17 is concerned, flow tothe main burner is established. As a convenient means for controllingthe amount of maximum flow of fuel in the on position of the valve, avalve plug 93 may be threaded into the bore 91 as here illustrated topermit the extension of the plug down to and partially across the port92 so as to thereby selectively restrict, and thereby control, the fuelflow therethrough. A screw driver slot 94 or other convenient toolengaging form as desired may be provided on the outer side of plug valve93 so as to permit its ready adjustment in the field to accommodate forvarying fuel pressures that may be encountered. Preferably a closuremember 96 is provided at the outer end passage 92 vided in the plugvalve 83 an additional passage or port 99 leading from the interior bore91 to the outside of the plug in diametrically opposed relation to theport or and in position to register with the pilot gas inlet 19 beingthe terminal end of bypass passage 14 at the interior wall 84 of thecontrol valve housing. Port 99 is also provided with a circumferentiallyextending channel or groove 101 in the outer periphery of plug member83, and which here extends for about 90 around such periphery so as tosimultaneously connect inlet port 19 to outlet port 21 leading to thepilot burner in the light position (see Figure 4), port 21 being locatedat the same transverse plane as port 19. As will also be seen fromFigure 4, port 21 is the terminal end of passage 102 provided in thehousing and leading to a fitting 103 for a conduit 104 leading to thepilot burner. In the light position provision is made by the controlvalve to shut ofi the flow of fuel to the main burner outlet 20 whileproviding for the by-pass flow of pilot fuel as discussed. This is hereeffected by locating a solid peripheral portion 106 across port 20 inthe light position of the valve as illustrated in Figure 4.

The control valve is provided with a third position herein denoted asthe o position which is one rotated clockwise from the light positionand is illustrated in Figure 5. In this position it will be seen thatthe solid portion 106 is of such an extent as to continue to blockoifport 20 while a diametrically opposed solid portion 107 moves acrossthe pilot outlet port 21 thus shutting ofi fuel flow to both the mainand pilot burners.

The several combinations provided by the control valve are important andmay be summarized as follows. In the on position inlet 18, in constantcommunication with bore 91, is connected to both the main and pilotburner outlets 20 and 21 while the by-pass inlet port 19 is closed ofiby the solid portion 106 aforementioned. In the light position bothinlet ports 18 and 19 are connected to the pilot outlet port 21 whilethe main fuel port 20 is closed. In the off position both outlet ports20 and 21 are closed. The importance and automatic interaction of theseseveral combinations of the control valve with the re-set mechanism andauxiliary by-pass valve 16 will be more clearly understood in a completeanalysis of operation, a brief description of which follows.

Starting with the normal open or run position of the mechanism asillustrated in Figures 3 and 7, and assuming the pilot burner properlyoperating, the thermo-couple heated and the magnet thereby energized,armature 31 will be retained in caught position 'thereby holding part 52in a retracted position immobilizing spring 54, and permitting the valve11 to be in open position under the influence of its opening spring 53.In this position of the parts fuel may flow from inlet 23 into chamber26 past open valve 11 and through passage 12 into the central inlet 18of the rotary plug valve 83. At the control valve and as seen in Figure3 of the drawing, fuel may pass from passage 91 through registeringports 92 and of bore 91, the member having the additional function in 20to the main burner. At the same time fuel may pass from passage 91through aligned ports 99 and 21 to the pilot burner.

Should the pilot burner be extinguished for any reason, the thermocouplewill cool thereby diminishing the electric potential applied to winding28 and the consequent magnetic field thereby releasing armature 31 fromits caught position for displacement by spring 54 to its .releasedposition as illustrated in Figure 2. In this movement part 52 engagesthe so-called level portion of the wedge member and swings the latterforcibly against valve 11 to effect its closing against the resistanceof spring 53. With main valve 11 closed, fuel flow is shut off to bothmain and pilot burners, since as will be seen from Figure 3 both outletports 20 and 21 depend on fuel from the inlet port 18 which is in turncontrolled by valve 11. It should also-be noted that in this on positionof the valve by-pass port 19 is closed. This is important in renderingnon-operative the resetting operation when the control valve is in onposition. If the reset is depressed, the Opcning of auxiliary valve 16will have no effect since the terminal end 19 of passage 14 is closed atthe control valve. Also the insertion of wedge member 57 between valve11 and part 52 will maintain the valve in tightly seated position whiledisplacing the armature 31 to the pole faces 32. However, since there isno pilot flame or resulting magnetic field, the armature is not held inattracted position but will follow back over the inclined sides of thewedge member as the latter is retracted by spring 54 upon manual releaseof the reset. During such retraction spring 54 operating through part 52and wedge member 57 constantly holds the valve 11 in closed position.

It is accordingly necessary in the operation of the present device toturn the manual control valve 17 to its light position in order tore-establish operations of the appliance. In this position of thecontrol "alve, as illustrated in Figure 4, fuel flow through the controlvalve is, as above noted, permitted from both inlets 18 and 19 to pilotoutlet 21 while main burner outlet 24 is shut off. As the reset shaft 61is depressed, as illustrated in Figure 6, valve 16 opens therebyestablishing pilot flow from the upstream side of valve 11 to the pilotburner which may be ignited. l t is important to note that the controlvalve effectively blocks any flow to the main burner port 20 from theby-pass inlet port 19. In the depressing of the reset shaft 61, wedgemember 57 serves to hold valve ll. closed while displacing armature 31to the pole faces 32 as shown in Figure 6. The operator needs to holdthe reset depressed for a sufiicient period after lighting of the pilotburner to provide an energizing of the magnetic field and resulting inholding of the armature. If the reset is not held for this requisiteperiod no harm will be done since the armature will merely return to itsreleased position during the course of which valve 11 is constantly heldin closed position by spring 54 as illustrated in Figure 2. However, byholding the reset in depressed position for the requisite time toestablish the magnetic field, armature 31 will be held in attracted orcaught position, as shown in Figure 7, thereby immobilizing spring 54.Ensuing releasing of the reset will permit valve 11 to open under theaction of its spring 53 while pivotally displacing wedge member 57around its connection with the reset shaft 61. With the main valve thusopened, there is still no flow to the main burner until the controlvalve is moved to on position. Also, it will be noted that immediatelyupon opening of main valve 11, pilot port 21 receives fuel from the maininlet 18 of the control valve by way of circumferential groove 101.Since this groove remains in constant registration with port 21 uponrotation of the control valve from light to on position, see Figures 3and 4, there is no interruption of the pilot burner occasioned by thischange of the control valve. It will thus be apparent that noinadvertent operation of either the reset mechanism or control valve canin any way interfere with or prevent the 100% or safe lightingcharacteristics of the present mechanism, but on the contrary suchcomplete safety features are at all times assured and automaticallyprovided for.

When desired and for convenience in shutting down the heat appliance,the manual control valve may be turned to its off position asillustrated in Figure thereby shutting oif the flow to both the main andpilot burners. The extinguishing of the pilot burner causes an ensuing rlease and shutting olf of main control valve 11 so that fuel flow isdoubly checked at all points. If, instead of wishing to completely closedown the operation of the appliance, it is desired to leave theappliance in a standby conditicn, the control valve may be moved tolight position, thereby effectively shutting off the flow of fuel to themain burner while leaving the pilot burner in operation. The appliancemay be thereafter put in operation by merely changing the control valvefrom its light to its on position.

I claim:

1. A pilot operated valve comprising, a valve member movable betweenopen and closed positions, thermostat means responsive to a pilot burnerflame and including a part movable between caught and releasedpositions, spring means engaging said part and said valve member andurging said valve member into open and closed positions in accordancewith the caught and released positions respectively of said part, andreset means including a wedge shaped member mounted for joint movementwith said part and said valve member and being formed with oppositetapered sides slidably mounted upon and positioned between said part andvalve member for relative movement therebetween to selectively urge saidpart to caught position while holding said valve member in closedposition.

2. In a pilot controlled safety valve for heat appliances, a housing, avalve mounted in said housing and movable to open and closed positions,thermostatic means responsive to a pilot burner flame and including apart mounted in said housing for movement coaxially of said valvebetween caught and released positions, said valve and part being formedwith axially opposed faces, spring means urging said valve and parttoward each other and to closed and released positions respectively, awedge shaped member positioned between said valve and part, formed withrelatively tapered sides slidably engaging said faces and said memberbeing mounted for joint movement with said valve and part and forreciprocal movement relative thereto perpendicular to the axis ofmovement of said valve and part, and an actuating member carried by saidhousing for reciprocation in alignment with said wedge member and beingpivotally secured thereto and extending from said housing for manualengagement and displacement, said wedge member being arranged ondisplacement in one direction by said actuating member to eifect arelative separation of said valve and part urging the latter to caughtposition while holding said valve in closed position against theresistance of said spring means, said wedge member being arranged ondisplacement in a return direction and with said part in caught positionto swing about its pivotal connection to said actuating member andrelease said valve for movement toward said part and to open positionunder the urge of said spring means.

3. In a fuel control mechanism of the character described, athermostatically controlled shut-off valve of the manually rcsettabletype responsive to the flame of a pilot burner and mounted in a passageproviding for and controlling the flow of fuel to a main burner of aheat appliance, manually engageable and displaceable rcset means forsaid valve, a passage by-passing said valve from the upstream sidethereof, a second valve mounted in said by-pass passage and connected tosaid reset means .for displacement thereby from a normally closedposition to an open position during the resetting operation, a thirdvalve of the multiple passage and position type having first and secondinlets connected to said first and second named passages respectivelyand first and second outlets adapted for connection to the main andpilot burners respectively, said third named valve having a firstposition connecting said first inlet with said first and second outletswhile closing off said second inlet, and said third valve having asecond position connecting said first and second inlets with said secondoutlet while closing said first outlet.

4. A fuel control mechanism as defined in claim 3 wherein said thirdvalve is provided with a third position closing off both said first andsecond outlets.

5. A safety valve for a fuel system comprising, a housing having firstand second passages therethrough adapted for communication to a fuelsource and to heating means including main and pilot burners, a springactuated main valve disposed Within said first passage and having anormally open position allowing fuel flow through said first passage anda closed position closing said passage, thermostatic means responsive tosaid pilot burner and including a part having caught and releasedpositions, said part being spring actuated and connected to said mainvalve to move the latter into closed position when said part is inreleased position but permitting the opening of said main valve when incaught position, reset means of wedge shape engaging said main valve andbeing displaceable in one direction to hold said main valve in closedposition and said part in caught position and displaceable in a returndirection to release said main valve to move to normal open position, amanually operated control valve having first and second inlets connectedto said first and second passages respectively on the discharge side ofsaid main valve and having first and second outlets adapted forconnection to the main and pilot burners respectively and having off,on, and light positions, said control valve in said 011 position closingboth said outlets, said control valve in said on position connectingsaid first inlet to both said outlets while closing said second inlet,said control valve in said light position connecting said first andsecond inlets to said second outlet while closing said first outlet, anda valve disposed in said second passage and connected to said resetmeans and displaced thereby to open position when said reset means isdisplaced in said first named direction and to closed position when saidreset means is displaced in said return direction.

6. In a fuel control mechanism of the character de scribed, a housingformed with a main fuel passage for supplying fuel to main and pilotburners of a heat appliance, a thermostatically controlled shut-offvalve of the manually resettable type mounted in said passage and beingresponsive to the flame of the pilot burner, manually engageable anddisplaceablereset means for said valve, an auxiliary passage connectedto said main passage at the upstream side of said valve, a second valvemounted in said auxiliary passage and connected to said reset means fordisplacement thereby from a normally closed position to an open positionduring the resetting operation, and a manually engageable rotary plugvalve journaled for rotation in said housing in a communication withsaid main and auxiliary passages, said housing being formed with mainand auxiliary outlets communicating with said plug valve, said plugvalve having on, light and oif positions and being formed to provide insaid on position for the communication of said main passage with saidmain and auxiliary outlets while closing off said auxiliary passage andbeing formed to provide in said light position for the communication ofsaid main and auxiliary passages with said auxiliary outlet whileclosing ott said main outlet and being formed to provide in said offposition for the closing 01f of both said main and auxiliary outlets.

7. A pilot operated safety valve comprising, a housing, a valve membermounted therein and movable between open and closed positions andincluding a co-axially extending valve stem, thermostatic meansresponsive .to a pilot burner flame and including a part slidablymounted on said valve stem for movement between caught and releasedpositions, spring means engaging said part and said valve member andurging said valve member into open position when said part is in thecaught position and urging said valve member into closed position whensaid part is in the released position, a generally U-shaped reset memberhaving a pair of spaced parallel legs mounted on opposite sides of saidstem between said valve member and part, and a manually engageable resetstern carried by said housing and having an articulated connection tosaid reset member for permitting reciprocal displacement of said legstransversely of said stem and movement of said legs jointly with saidvalve member and part axially of said stern, said legs being formed withopposite tapered sides slidably engaging said valve member and partwhereby upon transverse displacement of said reset member by said resetstem said part will be displaced to caught position while said valvemember is simultaneously displaced to closed position.

References Cited in the file of this patent UNITED STATES PATENTS Re.22,068 Joseting Apr. 4, 1942 2,309,709 Paille Feb. 2, 1943 2,361,945Jackson Nov. 7, 1944 2,362,011 Jeff-ers Nov. 7, 1944 2,372,537 WantzMar. 27, 1945 2,455,542 Weber Dec. 7, 1948 2,590,674 Bodey Mar. 25, 19522,591,897 Weber Apr. 8, 1952 2,604,107 Huntington July 22, 19522,616,710 Woodruff Nov. 4, 1952 FOREIGN PATENTS 218,209 Great Britain of1924 232,331 Switzerland of 1944

